This invention relates generally to computer modeling, and more specifically to computer modeling of cloth animation.
A common application for computers is three-dimensional (3D) modeling of objects, and the modeling of the animation of such objects. The modeling of rigid objects, such as automotive parts, human forms, etc., is fairly well developed within the prior art, including the modeling of the animation of such rigid objects in real-time. For example, with a relatively standard computer in terms of performance, rigid objects can be rotated and otherwise animated in real-time at fairly good speeds.
Conversely, however, the modeling of cloth, and the modeling of the animation of cloth, is not as well defined within the prior art. Cloth is generally difficult to model because it is not rigid, and thus reacts differently to forces such as wind, and also reacts and interacts differently with other objects that may be modeled. The modeling of the behavior of cloth is nevertheless important for the realistic animation of virtual worlds inhabited by people, for textile industry applications, etc.
Some current prior art cloth animation models treat cloth as a large number of coupled particles, where each particle is coupled to at least its nearest neighbors (usually, at least eight). While this achieves a certain degree of realism in animating cloth, the result is a set of complicated equations that are difficult to solve in real-time for even the most powerful commonly available computers. For example, it may take more than fifteen seconds to render a frame of animation of cloth, which effectively means that real-time animation is not possible.
Therefore, there is a need for models for cloth that provide for animation thereof substantially in real-time. For this and other reasons, there is a need for the present invention.
The invention relates to a model for cloth, such that the cloth can be animated in substantially real-time. In one embodiment, the latitudinal (or, vertical) nodes of a model for cloth are decoupled from the longitudinal (or, horizontal) nodes of the model. In one embodiment, a method first includes modeling the latitudinal nodes as physical splines, and then modeling the longitudinal nodes as stiff multi-section rods between horizontally adjacent latitudinal nodes. The term stiff can also be referred to as spline length preserving. The term multi-section rods can also be referred to as benders, or bended rods. The model is then rendered.
Embodiments of the invention provide for advantages not found within the prior art. Decoupling the latitudinal nodes from the longitudinal nodes in one embodiment provides for a mathematically simpler model of cloth, allowing for substantially faster frame-rendering times as compared to the prior art. This in turn allows for substantially real-time animation of the cloth.
The invention includes computer-implemented methods, machine-readable media, computerized systems, and computers of varying scopes. Other aspects, embodiments and advantages of the invention, beyond those described here, will become apparent by reading the detailed description and with reference to the drawings.